It was not a voltage issue that caused the fire. It was a case of not properly protecting the battery from vibration which resulted in the battery shorting out. It is safe to use Li-poly but if a battery system is made that can stand up to vibrations better and still give the same voltage/run times and be very close to the same in price, why not use it

Heck I use Thunder Power Li-Poly 3-cell 11.1 volt 1320mah which is a very common battery for small electric planes at roughly 2 ounces for my Sullivan smoke pump because they are very light and I have still yet to have to recharge it after 2 gallons of oil. I just have the battery wrapped really well in 1/4 inch thick foam, stuffed between some formers and NOT wire tied tightly down.

Aussie,

It's all about proper setup and protection of the batteries. The Duralites will be fine along with the power box you are thinking about. The Triton charger will work well for charging them

In my case I have 2 year old Li-ION's from Fromeco both in the 2400 and 4800 size. They show no sign of not taking a full charge even though Fromeco recommends replacing them every two years. I will carefully watch them